Highlighting priority areas for bovine viral diarrhea control in Italy : a phylogeographic approach

The prevalence and genetic diversity of bovine viral diarrhea virus (BVDV) in a geographic area are largely influenced by live animal trade and management practices. Despite control and eradication programs currently underway in several European countries, the risk of BVDV spread within and among countries is still present. BVDV-1 is the predominant type circulating in European cattle population. In this study, a phylogeographic analysis was applied to the BVDV-1 highest prevalent subtypes in Italy to reconstruct the origin and spatial-temporal distribution and to trace main viral flows between different locations to highlight priority areas for BVDV control. A comprehensive dataset of BVDV-1b (n\u202f=\u202f173) and 1e (n\u202f=\u202f172) 5' UTR sequences was analysed, including both novel and published sequences from Italy and from European countries bordering and/or with commercial cattle flows with Italy. A common phylogeographic pattern was observed for BVDV-1b and 1e subtypes: interspersion from multiple Italian areas and European countries was widespread until the end of the last century, whereas significant local clusters were observed starting from 2000. These findings support a continuous viral flow among different areas over long time scales with no evidence of significant geographical structure, while local transmission networks are limited to more recent years. Northern Italy has been confirmed as the area of origin of the main clades of both BVDV subtypes at national level, acting both as a crucial area for introduction and a maintenance source for other areas. Piedmont, Central and Southern Italian regions contributed to limited geographical distribution and local BVDV-1b and 1e persistence. On the whole, priority control measures for BVDV-1b and 1e in Italy should be focused on: i) implementation of BVDV systematic control in all Northern Italian regions to break the viral flow from larger to smaller animal populations; and ii) breaking the dynamics of infections in regions with self-maintenance of BVDV by voluntary control programs

Extended genetic diversity of bovine viral diarrhea virus and frequency of genotypes and subtypes in cattle in Italy between 1995 and 2013

Genetic typing of bovine viral diarrhea virus (BVDV) has distinguished BVDV-1 and BVDV-2 species and an emerging putative third species (HoBi-like virus), recently detected in southern Italy, signaling the occurrence of natural infection in Europe. Recognizing the need to update the data on BVDV genetic variability in Italy for mounting local and European alerts, a wide collection of 5 \u2032 UTR sequences (n = 371) was selected to identify the frequency of genotypes and subtypes at the herd level. BVDV-1 had the highest frequency, followed by sporadic BVDV-2. No novel HoBi-like viruses were identified. Four distribution patterns of BVDV-1 subtypes were observed: highly prevalent subtypes with a wide temporal-spatial distribution (1b and 1e), low prevalent subtypes with a widespread geographic distribution (1a, 1d, 1g, 1h, and 1k) or a restricted geographic distribution (1f), and sporadic subtypes detected only in single herds (1c, 1j, and 1l). BVDV-1c, k, and l are reported for the first time in Italy. A unique genetic variant was detected in the majority of herds, but cocirculation of genetic variants was also observed. Northern Italy ranked first for BVDV introduction, prevalence, and dispersion. Nevertheless, the presence of sporadic variants in other restricted areas suggests the risk of different routes of BVDV introduction

Evaluation of the enzyme-linked immunosorbent assay for the rapid screening and detection of classical swine fever virus antigens in the blood of pigs.

&lt;p&gt;A workshop was convened, at which seven enzyme-linked immunosorbent assays (ELISAs) were compared with virus isolation for the detection of viraemia in serial blood samples collected from six pigs at up to fourteen days after inoculation with classical swine fever virus. All ELISAs were of the double antibody sandwich type, using monoclonal and/or polyclonal antibodies to detect a variety of viral proteins in leukocytes, or in anti-coagulated blood or serum. Compared to virus isolation, specificity of the ELISA was good: only one sample found negative by virus isolation yielded a positive result in a single ELISA. Some false-negative results occurred with samples collected at up to eight days after inoculation, but all tests found samples collected between nine and fourteen days post-inoculation to be positive. The ELISAs require less-specialised facilities and can be performed much more rapidly than virus isolation. They are therefore extremely promising tools for screening large numbers of live pigs.&lt;/p&gt;</p

Sorveglianza sierologica in allevamenti suini del comprensorio umbro-marchigiano

In 7 allevamenti intensivi del territorio umbro-marchigiano \ue8 stata valutata la sieroprevalenza nei confronti di malattia di Aujeszky, Sindrome riproduttiva e respiratoria del suino (PRRS), Parvovirosi, Influenza, Micoplasmosi e Leptospirosi, nei riproduttori e nei soggetti all\u2019ingrasso. La sieroprevalenza \ue8 stata valutata in funzione della categoria produttiva (riproduttori, soggetti all\u2019ingrasso) e delle classi di et\ue0 degli animali esaminati. I profili sierologici aziendali non sono uniformi e tendono ad essere influenzati dall\u2019et\ue0 degli animali. In una sola azienda sono presenti scrofe sieropositive alla glicoproteina E del virus della malattia di Aujeszky. La massima prevalenza possibile dell\u2019infezione da virus della malattia di Aujeszky nelle aziende negative varia dall\u20198,7% al 17,8%

An in vivo pilot study to assess the antiviral efficacy of PA2 phytosome\uae in pigs experimentally infected with CSFV

Classical swine fever (CSF) is responsible of devastating outbreaks with high socio-economic impacts. Since vaccination has been banned in Europe, the current control systems are still based on massive culling of infected and suspect infected animals. Stamping out is considered a cost effective strategy, but it negatively impacts on community acceptance and animal welfare. For this reason use of antiviral drugs has been suggested as additional tool for controlling the spread of CSF as a good alternative to vaccination in offering an immediate protection. In the last few years the efficacy of 5-[(4-Bromophenyl)methyl]-2-phenyl-5H-imidazo[4,5-c]pyridine (BPIP), a representative of a class of imidazopyridines, has been demonstrated in vitro and in vivo. We and others have already demonstrated the efficacy of Proanthocyanidin A2 (PA2) against RNA viruses. In particular, preliminary results showed that this natural compound possesses an extracellular antiviral activity against animal pestiviruses. The aim of this study was to assess in vivo the antiviral activity of Proanthocyanidin A2 in the phytosome form, against CSFV. This formulation demonstrated greater affinity for the epithelial stratum corneum compared to the pure molecule itself, with the potential to enhance PA2 absorption through digestive mucosa. Specific-pathogen-free pigs (n=4) received a PA2 daily dose of 100 mg/kg (dry powder directly mixed in feed) for 15 consecutive days, starting 1 day before infection with the CSFV Alfort/187 strain. Pigs receiving PA2-free feed (n=4) were infected and housed in a separate isolation pen as a positive-control group. Treated pigs showed significantly lower clinical signs and a lower viral genome load compared to the controls. Such results seem to indicate that PA2 phytosome is able to reduce CSFV spread and suggest that it might be simply added to feed, thus being suitable to treat large numbers of animals in case of outbreak to exert either prophylactic and therapeutic effects

Classical swine fever virus: a ring test to evaluate RT-PCR detection methods.

&lt;p&gt;Six laboratories participated in an exercise to compare the sensitivity and specificity of RT-PCR tests for the detection of classical swine fever virus (CSFV). Two sets of coded samples were prepared by serial dilution of positive samples and then distributed to each of the laboratories. One set comprised 34 samples of random primed cDNA. These had been synthesised from viral RNA representative of seven different genetic subtypes of CSFV. The other set comprised 40 clinical samples containing tonsil, spleen, whole blood or serum from a pig that had been experimentally infected with CSFV. Each laboratory tested the samples using one or more PCR/RT-PCR tests that they were accustomed to using. The methods and results of the laboratories were compared with one another. The RT-PCR results obtained from testing the clinical samples were also compared with those obtained by virus isolation and antigen ELISA.ELISA. Both RT-PCR and RT-nested PCR appeared to give some false positive results. Several of the PCR tests appear suitable in terms of specificity and sensitivity. Further trials are necessary to compare results when the same test is performed by different laboratories, and to show that improved control procedures can eliminate problems due to false positive reactions.A limited comparison of extraction and reverse transcription procedures showed similar results in each of three participating laboratories, even though the methods were not standardised.&lt;/p&gt;</p

Molecular epidemiology of a large classical swine fever epidemic in the European Union in 1997-1998.

&lt;p&gt;A big epidemic of classical swine fever (CSF) occurred in the European Community in 1997. The first case was reported at the beginning of January 1997 from Germany. The disease presumably spread to the Netherlands, and from there to Italy, Spain and eventually to Belgium. About 30 isolates from these outbreaks were analysed by comparison of the nucleotide sequence data generated from fragments of both the E2 glycoprotein gene (190 nucleotides) and from the 5&#039;-nontranslated region (5&#039;-NTR; 150 nucleotides). By combining epidemiological data with genetic typing, it was found that the outbreaks were related and caused by a virus belonging to the genetic subgroup 2.1. As this type of virus had been reported infrequently in Europe and not at all since 1993, we postulate that it was newly introduced into the European Union (EU).&lt;/p&gt;</p